The above fan case for covering the fan blades of an aircraft jet engine is required to be lightweight and have high strength, and in order to meet these requirements, there are attempts of adopting a composite material consisting of reinforcing fibers and a thermosetting resin as the raw material of the fan case.
In the above fan case, an outward flange, on which, for example, a structure such as a gear box is mounted, or depending on the design, which can be part of a structure for coupling the jet engine with a wing or a structure for transmitting the jet engine thrust to the airframe, is disposed annularly along a circumferential direction in an intermediate part of a case main body which covers the fan blades and forms a cylindrical shape. A composite material consisting of reinforcing fibers such as carbon fibers and a thermosetting resin such as an epoxy resin is beginning to be adopted as the raw material of this outward flange as with the case main body.
Examples of the outward flange for which this composite material is beginning to be adopted include the one described in Patent Document 1. This outward flange includes a flange main body layer which forms an annular flange main body part extending along the circumferential direction of the case main body, and an adherent support layer which fixes the flange main body layer on the outer peripheral surface of the case main body while supporting the flange main body layer from both sides. Both the flange main body layer and the adherent support layer are formed by laminating a plurality of fabric layers including a fabric composed of reinforcing fibers such as carbon fibers.
In the manufacture of a fan case (cylindrical case) by forming the above-described outward flange on the outer peripheral surface of the case main body, first, a laminate is molded by laying a plurality of fabric layers on top of one another, and the thermosetting resin, with which the fabric layers are pre-impregnated, is cured by heating this laminate to form the flange main body layer.
Next, the flange main body layer is disposed along the circumferential direction on the outer peripheral surface of the case main body which is made of a composite material consisting of reinforcing fibers and a thermosetting resin, and after a plurality of fabric layers are laminated on both sides of this flange main body layer and molded as the adherent support layer, the flange main body layer is fixed on the outer peripheral surface of the case main body by heating the adherent support layer and curing the thermosetting resin in the same manner as with the flange main body layer.